Add m-esr52 at 52.6.0

1 files changed, 1285 insertions, 0 deletions

diff --git a/dom/network/NetworkStatsDB.jsm b/dom/network/NetworkStatsDB.jsm
new file mode 100644
index 0000000000..aa74d40ad9
--- /dev/null
+++ b/dom/network/NetworkStatsDB.jsm
@@ -0,0 +1,1285 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+this.EXPORTED_SYMBOLS = ['NetworkStatsDB'];
+
+const DEBUG = false;
+function debug(s) { dump("-*- NetworkStatsDB: " + s + "\n"); }
+
+const {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components;
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/IndexedDBHelper.jsm");
+Cu.importGlobalProperties(["indexedDB"]);
+
+XPCOMUtils.defineLazyServiceGetter(this, "appsService",
+                                   "@mozilla.org/AppsService;1",
+                                   "nsIAppsService");
+
+const DB_NAME = "net_stats";
+const DB_VERSION = 9;
+const DEPRECATED_STATS_STORE_NAME =
+  [
+    "net_stats_v2",    // existed only in DB version 2
+    "net_stats",       // existed in DB version 1 and 3 to 5
+    "net_stats_store", // existed in DB version 6 to 8
+  ];
+const STATS_STORE_NAME = "net_stats_store_v3"; // since DB version 9
+const ALARMS_STORE_NAME = "net_alarm";
+
+// Constant defining the maximum values allowed per interface. If more, older
+// will be erased.
+const VALUES_MAX_LENGTH = 6 * 30;
+
+// Constant defining the rate of the samples. Daily.
+const SAMPLE_RATE = 1000 * 60 * 60 * 24;
+
+this.NetworkStatsDB = function NetworkStatsDB() {
+  if (DEBUG) {
+    debug("Constructor");
+  }
+  this.initDBHelper(DB_NAME, DB_VERSION, [STATS_STORE_NAME, ALARMS_STORE_NAME]);
+}
+
+NetworkStatsDB.prototype = {
+  __proto__: IndexedDBHelper.prototype,
+
+  dbNewTxn: function dbNewTxn(store_name, txn_type, callback, txnCb) {
+    function successCb(result) {
+      txnCb(null, result);
+    }
+    function errorCb(error) {
+      txnCb(error, null);
+    }
+    return this.newTxn(txn_type, store_name, callback, successCb, errorCb);
+  },
+
+  /**
+   * The onupgradeneeded handler of the IDBOpenDBRequest.
+   * This function is called in IndexedDBHelper open() method.
+   *
+   * @param {IDBTransaction} aTransaction
+   *        {IDBDatabase} aDb
+   *        {64-bit integer} aOldVersion The version number on local storage.
+   *        {64-bit integer} aNewVersion The version number to be upgraded to.
+   *
+   * @note  Be careful with the database upgrade pattern.
+   *        Because IndexedDB operations are performed asynchronously, we must
+   *        apply a recursive approach instead of an iterative approach while
+   *        upgrading versions.
+   */
+  upgradeSchema: function upgradeSchema(aTransaction, aDb, aOldVersion, aNewVersion) {
+    if (DEBUG) {
+      debug("upgrade schema from: " + aOldVersion + " to " + aNewVersion + " called!");
+    }
+    let db = aDb;
+    let objectStore;
+
+    // An array of upgrade functions for each version.
+    let upgradeSteps = [
+      function upgrade0to1() {
+        if (DEBUG) debug("Upgrade 0 to 1: Create object stores and indexes.");
+
+        // Create the initial database schema.
+        objectStore = db.createObjectStore(DEPRECATED_STATS_STORE_NAME[1],
+                                           { keyPath: ["connectionType", "timestamp"] });
+        objectStore.createIndex("connectionType", "connectionType", { unique: false });
+        objectStore.createIndex("timestamp", "timestamp", { unique: false });
+        objectStore.createIndex("rxBytes", "rxBytes", { unique: false });
+        objectStore.createIndex("txBytes", "txBytes", { unique: false });
+        objectStore.createIndex("rxTotalBytes", "rxTotalBytes", { unique: false });
+        objectStore.createIndex("txTotalBytes", "txTotalBytes", { unique: false });
+
+        upgradeNextVersion();
+      },
+
+      function upgrade1to2() {
+        if (DEBUG) debug("Upgrade 1 to 2: Do nothing.");
+        upgradeNextVersion();
+      },
+
+      function upgrade2to3() {
+        if (DEBUG) debug("Upgrade 2 to 3: Add keyPath appId to object store.");
+
+        // In order to support per-app traffic data storage, the original
+        // objectStore needs to be replaced by a new objectStore with new
+        // key path ("appId") and new index ("appId").
+        // Also, since now networks are identified by their
+        // [networkId, networkType] not just by their connectionType,
+        // to modify the keyPath is mandatory to delete the object store
+        // and create it again. Old data is going to be deleted because the
+        // networkId for each sample can not be set.
+
+        // In version 1.2 objectStore name was 'net_stats_v2', to avoid errors when
+        // upgrading from 1.2 to 1.3 objectStore name should be checked.
+        let stores = db.objectStoreNames;
+        let deprecatedName = DEPRECATED_STATS_STORE_NAME[0];
+        let storeName = DEPRECATED_STATS_STORE_NAME[1];
+        if(stores.contains(deprecatedName)) {
+          // Delete the obsolete stats store.
+          db.deleteObjectStore(deprecatedName);
+        } else {
+          // Re-create stats object store without copying records.
+          db.deleteObjectStore(storeName);
+        }
+
+        objectStore = db.createObjectStore(storeName, { keyPath: ["appId", "network", "timestamp"] });
+        objectStore.createIndex("appId", "appId", { unique: false });
+        objectStore.createIndex("network", "network", { unique: false });
+        objectStore.createIndex("networkType", "networkType", { unique: false });
+        objectStore.createIndex("timestamp", "timestamp", { unique: false });
+        objectStore.createIndex("rxBytes", "rxBytes", { unique: false });
+        objectStore.createIndex("txBytes", "txBytes", { unique: false });
+        objectStore.createIndex("rxTotalBytes", "rxTotalBytes", { unique: false });
+        objectStore.createIndex("txTotalBytes", "txTotalBytes", { unique: false });
+
+        upgradeNextVersion();
+      },
+
+      function upgrade3to4() {
+        if (DEBUG) debug("Upgrade 3 to 4: Delete redundant indexes.");
+
+        // Delete redundant indexes (leave "network" only).
+        objectStore = aTransaction.objectStore(DEPRECATED_STATS_STORE_NAME[1]);
+        if (objectStore.indexNames.contains("appId")) {
+          objectStore.deleteIndex("appId");
+        }
+        if (objectStore.indexNames.contains("networkType")) {
+          objectStore.deleteIndex("networkType");
+        }
+        if (objectStore.indexNames.contains("timestamp")) {
+          objectStore.deleteIndex("timestamp");
+        }
+        if (objectStore.indexNames.contains("rxBytes")) {
+          objectStore.deleteIndex("rxBytes");
+        }
+        if (objectStore.indexNames.contains("txBytes")) {
+          objectStore.deleteIndex("txBytes");
+        }
+        if (objectStore.indexNames.contains("rxTotalBytes")) {
+          objectStore.deleteIndex("rxTotalBytes");
+        }
+        if (objectStore.indexNames.contains("txTotalBytes")) {
+          objectStore.deleteIndex("txTotalBytes");
+        }
+
+        upgradeNextVersion();
+      },
+
+      function upgrade4to5() {
+        if (DEBUG) debug("Upgrade 4 to 5: Create object store for alarms.");
+
+        // In order to manage alarms, it is necessary to use a global counter
+        // (totalBytes) that will increase regardless of the system reboot.
+        objectStore = aTransaction.objectStore(DEPRECATED_STATS_STORE_NAME[1]);
+
+        // Now, systemBytes will hold the old totalBytes and totalBytes will
+        // keep the increasing counter. |counters| will keep the track of
+        // accumulated values.
+        let counters = {};
+
+        objectStore.openCursor().onsuccess = function(event) {
+          let cursor = event.target.result;
+          if (!cursor){
+            // upgrade4to5 completed now.
+            upgradeNextVersion();
+            return;
+          }
+
+          cursor.value.rxSystemBytes = cursor.value.rxTotalBytes;
+          cursor.value.txSystemBytes = cursor.value.txTotalBytes;
+
+          if (cursor.value.appId == 0) {
+            let netId = cursor.value.network[0] + '' + cursor.value.network[1];
+            if (!counters[netId]) {
+              counters[netId] = {
+                rxCounter: 0,
+                txCounter: 0,
+                lastRx: 0,
+                lastTx: 0
+              };
+            }
+
+            let rxDiff = cursor.value.rxSystemBytes - counters[netId].lastRx;
+            let txDiff = cursor.value.txSystemBytes - counters[netId].lastTx;
+            if (rxDiff < 0 || txDiff < 0) {
+              // System reboot between samples, so take the current one.
+              rxDiff = cursor.value.rxSystemBytes;
+              txDiff = cursor.value.txSystemBytes;
+            }
+
+            counters[netId].rxCounter += rxDiff;
+            counters[netId].txCounter += txDiff;
+            cursor.value.rxTotalBytes = counters[netId].rxCounter;
+            cursor.value.txTotalBytes = counters[netId].txCounter;
+
+            counters[netId].lastRx = cursor.value.rxSystemBytes;
+            counters[netId].lastTx = cursor.value.txSystemBytes;
+          } else {
+            cursor.value.rxTotalBytes = cursor.value.rxSystemBytes;
+            cursor.value.txTotalBytes = cursor.value.txSystemBytes;
+          }
+
+          cursor.update(cursor.value);
+          cursor.continue();
+        };
+
+        // Create object store for alarms.
+        objectStore = db.createObjectStore(ALARMS_STORE_NAME, { keyPath: "id", autoIncrement: true });
+        objectStore.createIndex("alarm", ['networkId','threshold'], { unique: false });
+        objectStore.createIndex("manifestURL", "manifestURL", { unique: false });
+      },
+
+      function upgrade5to6() {
+        if (DEBUG) debug("Upgrade 5 to 6: Add keyPath serviceType to object store.");
+
+        // In contrast to "per-app" traffic data, "system-only" traffic data
+        // refers to data which can not be identified by any applications.
+        // To further support "system-only" data storage, the data can be
+        // saved by service type (e.g., Tethering, OTA). Thus it's needed to
+        // have a new key ("serviceType") for the ojectStore.
+        let newObjectStore;
+        let deprecatedName = DEPRECATED_STATS_STORE_NAME[1];
+        newObjectStore = db.createObjectStore(DEPRECATED_STATS_STORE_NAME[2],
+                         { keyPath: ["appId", "serviceType", "network", "timestamp"] });
+        newObjectStore.createIndex("network", "network", { unique: false });
+
+        // Copy the data from the original objectStore to the new objectStore.
+        objectStore = aTransaction.objectStore(deprecatedName);
+        objectStore.openCursor().onsuccess = function(event) {
+          let cursor = event.target.result;
+          if (!cursor) {
+            db.deleteObjectStore(deprecatedName);
+            // upgrade5to6 completed now.
+            upgradeNextVersion();
+            return;
+          }
+
+          let newStats = cursor.value;
+          newStats.serviceType = "";
+          newObjectStore.put(newStats);
+          cursor.continue();
+        };
+      },
+
+      function upgrade6to7() {
+        if (DEBUG) debug("Upgrade 6 to 7: Replace alarm threshold by relativeThreshold.");
+
+        // Replace threshold attribute of alarm index by relativeThreshold in alarms DB.
+        // Now alarms are indexed by relativeThreshold, which is the threshold relative
+        // to current system stats.
+        let alarmsStore = aTransaction.objectStore(ALARMS_STORE_NAME);
+
+        // Delete "alarm" index.
+        if (alarmsStore.indexNames.contains("alarm")) {
+          alarmsStore.deleteIndex("alarm");
+        }
+
+        // Create new "alarm" index.
+        alarmsStore.createIndex("alarm", ['networkId','relativeThreshold'], { unique: false });
+
+        // Populate new "alarm" index attributes.
+        alarmsStore.openCursor().onsuccess = function(event) {
+          let cursor = event.target.result;
+          if (!cursor) {
+            upgrade6to7_updateTotalBytes();
+            return;
+          }
+
+          cursor.value.relativeThreshold = cursor.value.threshold;
+          cursor.value.absoluteThreshold = cursor.value.threshold;
+          delete cursor.value.threshold;
+
+          cursor.update(cursor.value);
+          cursor.continue();
+        }
+
+        function upgrade6to7_updateTotalBytes() {
+          if (DEBUG) debug("Upgrade 6 to 7: Update TotalBytes.");
+          // Previous versions save accumulative totalBytes, increasing although the system
+          // reboots or resets stats. But is necessary to reset the total counters when reset
+          // through 'clearInterfaceStats'.
+          let statsStore = aTransaction.objectStore(DEPRECATED_STATS_STORE_NAME[2]);
+          let networks = [];
+
+          // Find networks stored in the database.
+          statsStore.index("network").openKeyCursor(null, "nextunique").onsuccess = function(event) {
+            let cursor = event.target.result;
+
+            // Store each network into an array.
+            if (cursor) {
+              networks.push(cursor.key);
+              cursor.continue();
+              return;
+            }
+
+            // Start to deal with each network.
+            let pending = networks.length;
+
+            if (pending === 0) {
+              // Found no records of network. upgrade6to7 completed now.
+              upgradeNextVersion();
+              return;
+            }
+
+            networks.forEach(function(network) {
+              let lowerFilter = [0, "", network, 0];
+              let upperFilter = [0, "", network, ""];
+              let range = IDBKeyRange.bound(lowerFilter, upperFilter, false, false);
+
+              // Find number of samples for a given network.
+              statsStore.count(range).onsuccess = function(event) {
+                let recordCount = event.target.result;
+
+                // If there are more samples than the max allowed, there is no way to know
+                // when does reset take place.
+                if (recordCount === 0 || recordCount >= VALUES_MAX_LENGTH) {
+                  pending--;
+                  if (pending === 0) {
+                    upgradeNextVersion();
+                  }
+                  return;
+                }
+
+                let last = null;
+                // Reset detected if the first sample totalCounters are different than bytes
+                // counters. If so, the total counters should be recalculated.
+                statsStore.openCursor(range).onsuccess = function(event) {
+                  let cursor = event.target.result;
+                  if (!cursor) {
+                    pending--;
+                    if (pending === 0) {
+                      upgradeNextVersion();
+                    }
+                    return;
+                  }
+                  if (!last) {
+                    if (cursor.value.rxTotalBytes == cursor.value.rxBytes &&
+                        cursor.value.txTotalBytes == cursor.value.txBytes) {
+                      pending--;
+                      if (pending === 0) {
+                        upgradeNextVersion();
+                      }
+                      return;
+                    }
+
+                    cursor.value.rxTotalBytes = cursor.value.rxBytes;
+                    cursor.value.txTotalBytes = cursor.value.txBytes;
+                    cursor.update(cursor.value);
+                    last = cursor.value;
+                    cursor.continue();
+                    return;
+                  }
+
+                  // Recalculate the total counter for last / current sample
+                  cursor.value.rxTotalBytes = last.rxTotalBytes + cursor.value.rxBytes;
+                  cursor.value.txTotalBytes = last.txTotalBytes + cursor.value.txBytes;
+                  cursor.update(cursor.value);
+                  last = cursor.value;
+                  cursor.continue();
+                }
+              }
+            }, this); // end of networks.forEach()
+          }; // end of statsStore.index("network").openKeyCursor().onsuccess callback
+        } // end of function upgrade6to7_updateTotalBytes
+      },
+
+      function upgrade7to8() {
+        if (DEBUG) debug("Upgrade 7 to 8: Create index serviceType.");
+
+        // Create index for 'ServiceType' in order to make it retrievable.
+        let statsStore = aTransaction.objectStore(DEPRECATED_STATS_STORE_NAME[2]);
+        statsStore.createIndex("serviceType", "serviceType", { unique: false });
+
+        upgradeNextVersion();
+      },
+
+      function upgrade8to9() {
+        if (DEBUG) debug("Upgrade 8 to 9: Add keyPath isInBrowser to " +
+                         "network stats object store");
+
+        // Since B2G v2.0, there is no stand-alone browser app anymore.
+        // The browser app is a mozbrowser iframe element owned by system app.
+        // In order to separate traffic generated from system and browser, we
+        // have to add a new attribute |isInBrowser| as keyPath.
+        // Refer to bug 1070944 for more detail.
+        let newObjectStore;
+        let deprecatedName = DEPRECATED_STATS_STORE_NAME[2];
+        newObjectStore = db.createObjectStore(STATS_STORE_NAME,
+                         { keyPath: ["appId", "isInBrowser", "serviceType",
+                                     "network", "timestamp"] });
+        newObjectStore.createIndex("network", "network", { unique: false });
+        newObjectStore.createIndex("serviceType", "serviceType", { unique: false });
+
+        // Copy records from the current object store to the new one.
+        objectStore = aTransaction.objectStore(deprecatedName);
+        objectStore.openCursor().onsuccess = function (event) {
+          let cursor = event.target.result;
+          if (!cursor) {
+            db.deleteObjectStore(deprecatedName);
+            // upgrade8to9 completed now.
+            return;
+          }
+          let newStats = cursor.value;
+          // Augment records by adding the new isInBrowser attribute.
+          // Notes:
+          // 1. Key value cannot be boolean type. Use 1/0 instead of true/false.
+          // 2. Most traffic of system app should come from its browser iframe,
+          //    thus assign isInBrowser as 1 for system app.
+          let manifestURL = appsService.getManifestURLByLocalId(newStats.appId);
+          if (manifestURL && manifestURL.search(/app:\/\/system\./) === 0) {
+            newStats.isInBrowser = 1;
+          } else {
+            newStats.isInBrowser = 0;
+          }
+          newObjectStore.put(newStats);
+          cursor.continue();
+        };
+      }
+    ];
+
+    let index = aOldVersion;
+    let outer = this;
+
+    function upgradeNextVersion() {
+      if (index == aNewVersion) {
+        debug("Upgrade finished.");
+        return;
+      }
+
+      try {
+        var i = index++;
+        if (DEBUG) debug("Upgrade step: " + i + "\n");
+        upgradeSteps[i].call(outer);
+      } catch (ex) {
+        dump("Caught exception " + ex);
+        throw ex;
+        return;
+      }
+    }
+
+    if (aNewVersion > upgradeSteps.length) {
+      debug("No migration steps for the new version!");
+      aTransaction.abort();
+      return;
+    }
+
+    upgradeNextVersion();
+  },
+
+  importData: function importData(aStats) {
+    let stats = { appId:         aStats.appId,
+                  isInBrowser:   aStats.isInBrowser ? 1 : 0,
+                  serviceType:   aStats.serviceType,
+                  network:       [aStats.networkId, aStats.networkType],
+                  timestamp:     aStats.timestamp,
+                  rxBytes:       aStats.rxBytes,
+                  txBytes:       aStats.txBytes,
+                  rxSystemBytes: aStats.rxSystemBytes,
+                  txSystemBytes: aStats.txSystemBytes,
+                  rxTotalBytes:  aStats.rxTotalBytes,
+                  txTotalBytes:  aStats.txTotalBytes };
+
+    return stats;
+  },
+
+  exportData: function exportData(aStats) {
+    let stats = { appId:        aStats.appId,
+                  isInBrowser:  aStats.isInBrowser ? true : false,
+                  serviceType:  aStats.serviceType,
+                  networkId:    aStats.network[0],
+                  networkType:  aStats.network[1],
+                  timestamp:    aStats.timestamp,
+                  rxBytes:      aStats.rxBytes,
+                  txBytes:      aStats.txBytes,
+                  rxTotalBytes: aStats.rxTotalBytes,
+                  txTotalBytes: aStats.txTotalBytes };
+
+    return stats;
+  },
+
+  normalizeDate: function normalizeDate(aDate) {
+    // Convert to UTC according to timezone and
+    // filter timestamp to get SAMPLE_RATE precission
+    let timestamp = aDate.getTime() - aDate.getTimezoneOffset() * 60 * 1000;
+    timestamp = Math.floor(timestamp / SAMPLE_RATE) * SAMPLE_RATE;
+    return timestamp;
+  },
+
+  saveStats: function saveStats(aStats, aResultCb) {
+    let isAccumulative = aStats.isAccumulative;
+    let timestamp = this.normalizeDate(aStats.date);
+
+    let stats = { appId:         aStats.appId,
+                  isInBrowser:   aStats.isInBrowser,
+                  serviceType:   aStats.serviceType,
+                  networkId:     aStats.networkId,
+                  networkType:   aStats.networkType,
+                  timestamp:     timestamp,
+                  rxBytes:       isAccumulative ? 0 : aStats.rxBytes,
+                  txBytes:       isAccumulative ? 0 : aStats.txBytes,
+                  rxSystemBytes: isAccumulative ? aStats.rxBytes : 0,
+                  txSystemBytes: isAccumulative ? aStats.txBytes : 0,
+                  rxTotalBytes:  isAccumulative ? aStats.rxBytes : 0,
+                  txTotalBytes:  isAccumulative ? aStats.txBytes : 0 };
+
+    stats = this.importData(stats);
+
+    this.dbNewTxn(STATS_STORE_NAME, "readwrite", function(aTxn, aStore) {
+      if (DEBUG) {
+        debug("Filtered time: " + new Date(timestamp));
+        debug("New stats: " + JSON.stringify(stats));
+      }
+
+      let lowerFilter = [stats.appId, stats.isInBrowser, stats.serviceType,
+                         stats.network, 0];
+      let upperFilter = [stats.appId, stats.isInBrowser, stats.serviceType,
+                         stats.network, ""];
+      let range = IDBKeyRange.bound(lowerFilter, upperFilter, false, false);
+
+      let request = aStore.openCursor(range, 'prev');
+      request.onsuccess = function onsuccess(event) {
+        let cursor = event.target.result;
+        if (!cursor) {
+          // Empty, so save first element.
+
+          if (!isAccumulative) {
+            this._saveStats(aTxn, aStore, stats);
+            return;
+          }
+
+          // There could be a time delay between the point when the network
+          // interface comes up and the point when the database is initialized.
+          // In this short interval some traffic data are generated but are not
+          // registered by the first sample.
+          stats.rxBytes = stats.rxTotalBytes;
+          stats.txBytes = stats.txTotalBytes;
+
+          // However, if the interface is not switched on after the database is
+          // initialized (dual sim use case) stats should be set to 0.
+          let req = aStore.index("network").openKeyCursor(null, "nextunique");
+          req.onsuccess = function onsuccess(event) {
+            let cursor = event.target.result;
+            if (cursor) {
+              if (cursor.key[1] == stats.network[1]) {
+                stats.rxBytes = 0;
+                stats.txBytes = 0;
+                this._saveStats(aTxn, aStore, stats);
+                return;
+              }
+
+              cursor.continue();
+              return;
+            }
+
+            this._saveStats(aTxn, aStore, stats);
+          }.bind(this);
+
+          return;
+        }
+
+        // There are old samples
+        if (DEBUG) {
+          debug("Last value " + JSON.stringify(cursor.value));
+        }
+
+        // Remove stats previous to now - VALUE_MAX_LENGTH
+        this._removeOldStats(aTxn, aStore, stats.appId, stats.isInBrowser,
+                             stats.serviceType, stats.network, stats.timestamp);
+
+        // Process stats before save
+        this._processSamplesDiff(aTxn, aStore, cursor, stats, isAccumulative);
+      }.bind(this);
+    }.bind(this), aResultCb);
+  },
+
+  /*
+   * This function check that stats are saved in the database following the sample rate.
+   * In this way is easier to find elements when stats are requested.
+   */
+  _processSamplesDiff: function _processSamplesDiff(aTxn,
+                                                    aStore,
+                                                    aLastSampleCursor,
+                                                    aNewSample,
+                                                    aIsAccumulative) {
+    let lastSample = aLastSampleCursor.value;
+
+    // Get difference between last and new sample.
+    let diff = (aNewSample.timestamp - lastSample.timestamp) / SAMPLE_RATE;
+    if (diff % 1) {
+      // diff is decimal, so some error happened because samples are stored as a multiple
+      // of SAMPLE_RATE
+      aTxn.abort();
+      throw new Error("Error processing samples");
+    }
+
+    if (DEBUG) {
+      debug("New: " + aNewSample.timestamp + " - Last: " +
+            lastSample.timestamp + " - diff: " + diff);
+    }
+
+    // If the incoming data has a accumulation feature, the new
+    // |txBytes|/|rxBytes| is assigend by differnces between the new
+    // |txTotalBytes|/|rxTotalBytes| and the last |txTotalBytes|/|rxTotalBytes|.
+    // Else, if incoming data is non-accumulative, the |txBytes|/|rxBytes|
+    // is the new |txBytes|/|rxBytes|.
+    let rxDiff = 0;
+    let txDiff = 0;
+    if (aIsAccumulative) {
+      rxDiff = aNewSample.rxSystemBytes - lastSample.rxSystemBytes;
+      txDiff = aNewSample.txSystemBytes - lastSample.txSystemBytes;
+      if (rxDiff < 0 || txDiff < 0) {
+        rxDiff = aNewSample.rxSystemBytes;
+        txDiff = aNewSample.txSystemBytes;
+      }
+      aNewSample.rxBytes = rxDiff;
+      aNewSample.txBytes = txDiff;
+
+      aNewSample.rxTotalBytes = lastSample.rxTotalBytes + rxDiff;
+      aNewSample.txTotalBytes = lastSample.txTotalBytes + txDiff;
+    } else {
+      rxDiff = aNewSample.rxBytes;
+      txDiff = aNewSample.txBytes;
+    }
+
+    if (diff == 1) {
+      // New element.
+
+      // If the incoming data is non-accumulative, the new
+      // |rxTotalBytes|/|txTotalBytes| needs to be updated by adding new
+      // |rxBytes|/|txBytes| to the last |rxTotalBytes|/|txTotalBytes|.
+      if (!aIsAccumulative) {
+        aNewSample.rxTotalBytes = aNewSample.rxBytes + lastSample.rxTotalBytes;
+        aNewSample.txTotalBytes = aNewSample.txBytes + lastSample.txTotalBytes;
+      }
+
+      this._saveStats(aTxn, aStore, aNewSample);
+      return;
+    }
+    if (diff > 1) {
+      // Some samples lost. Device off during one or more samplerate periods.
+      // Time or timezone changed
+      // Add lost samples with 0 bytes and the actual one.
+      if (diff > VALUES_MAX_LENGTH) {
+        diff = VALUES_MAX_LENGTH;
+      }
+
+      let data = [];
+      for (let i = diff - 2; i >= 0; i--) {
+        let time = aNewSample.timestamp - SAMPLE_RATE * (i + 1);
+        let sample = { appId:         aNewSample.appId,
+                       isInBrowser:   aNewSample.isInBrowser,
+                       serviceType:   aNewSample.serviceType,
+                       network:       aNewSample.network,
+                       timestamp:     time,
+                       rxBytes:       0,
+                       txBytes:       0,
+                       rxSystemBytes: lastSample.rxSystemBytes,
+                       txSystemBytes: lastSample.txSystemBytes,
+                       rxTotalBytes:  lastSample.rxTotalBytes,
+                       txTotalBytes:  lastSample.txTotalBytes };
+
+        data.push(sample);
+      }
+
+      data.push(aNewSample);
+      this._saveStats(aTxn, aStore, data);
+      return;
+    }
+    if (diff == 0 || diff < 0) {
+      // New element received before samplerate period. It means that device has
+      // been restarted (or clock / timezone change).
+      // Update element. If diff < 0, clock or timezone changed back. Place data
+      // in the last sample.
+
+      // Old |rxTotalBytes|/|txTotalBytes| needs to get updated by adding the
+      // last |rxTotalBytes|/|txTotalBytes|.
+      lastSample.rxBytes += rxDiff;
+      lastSample.txBytes += txDiff;
+      lastSample.rxSystemBytes = aNewSample.rxSystemBytes;
+      lastSample.txSystemBytes = aNewSample.txSystemBytes;
+      lastSample.rxTotalBytes += rxDiff;
+      lastSample.txTotalBytes += txDiff;
+
+      if (DEBUG) {
+        debug("Update: " + JSON.stringify(lastSample));
+      }
+      let req = aLastSampleCursor.update(lastSample);
+    }
+  },
+
+  _saveStats: function _saveStats(aTxn, aStore, aNetworkStats) {
+    if (DEBUG) {
+      debug("_saveStats: " + JSON.stringify(aNetworkStats));
+    }
+
+    if (Array.isArray(aNetworkStats)) {
+      let len = aNetworkStats.length - 1;
+      for (let i = 0; i <= len; i++) {
+        aStore.put(aNetworkStats[i]);
+      }
+    } else {
+      aStore.put(aNetworkStats);
+    }
+  },
+
+  _removeOldStats: function _removeOldStats(aTxn, aStore, aAppId, aIsInBrowser,
+                                            aServiceType, aNetwork, aDate) {
+    // Callback function to remove old items when new ones are added.
+    let filterDate = aDate - (SAMPLE_RATE * VALUES_MAX_LENGTH - 1);
+    let lowerFilter = [aAppId, aIsInBrowser, aServiceType, aNetwork, 0];
+    let upperFilter = [aAppId, aIsInBrowser, aServiceType, aNetwork, filterDate];
+    let range = IDBKeyRange.bound(lowerFilter, upperFilter, false, false);
+    let lastSample = null;
+    let self = this;
+
+    aStore.openCursor(range).onsuccess = function(event) {
+      var cursor = event.target.result;
+      if (cursor) {
+        lastSample = cursor.value;
+        cursor.delete();
+        cursor.continue();
+        return;
+      }
+
+      // If all samples for a network are removed, an empty sample
+      // has to be saved to keep the totalBytes in order to compute
+      // future samples because system counters are not set to 0.
+      // Thus, if there are no samples left, the last sample removed
+      // will be saved again after setting its bytes to 0.
+      let request = aStore.index("network").openCursor(aNetwork);
+      request.onsuccess = function onsuccess(event) {
+        let cursor = event.target.result;
+        if (!cursor && lastSample != null) {
+          let timestamp = new Date();
+          timestamp = self.normalizeDate(timestamp);
+          lastSample.timestamp = timestamp;
+          lastSample.rxBytes = 0;
+          lastSample.txBytes = 0;
+          self._saveStats(aTxn, aStore, lastSample);
+        }
+      };
+    };
+  },
+
+  clearInterfaceStats: function clearInterfaceStats(aNetwork, aResultCb) {
+    let network = [aNetwork.network.id, aNetwork.network.type];
+    let self = this;
+
+    // Clear and save an empty sample to keep sync with system counters
+    this.dbNewTxn(STATS_STORE_NAME, "readwrite", function(aTxn, aStore) {
+      let sample = null;
+      let request = aStore.index("network").openCursor(network, "prev");
+      request.onsuccess = function onsuccess(event) {
+        let cursor = event.target.result;
+        if (cursor) {
+          if (!sample && cursor.value.appId == 0) {
+            sample = cursor.value;
+          }
+
+          cursor.delete();
+          cursor.continue();
+          return;
+        }
+
+        if (sample) {
+          let timestamp = new Date();
+          timestamp = self.normalizeDate(timestamp);
+          sample.timestamp = timestamp;
+          sample.appId = 0;
+          sample.isInBrowser = 0;
+          sample.serviceType = "";
+          sample.rxBytes = 0;
+          sample.txBytes = 0;
+          sample.rxTotalBytes = 0;
+          sample.txTotalBytes = 0;
+
+          self._saveStats(aTxn, aStore, sample);
+        }
+      };
+    }, this._resetAlarms.bind(this, aNetwork.networkId, aResultCb));
+  },
+
+  clearStats: function clearStats(aNetworks, aResultCb) {
+    let index = 0;
+    let stats = [];
+    let self = this;
+
+    let callback = function(aError, aResult) {
+      index++;
+
+      if (!aError && index < aNetworks.length) {
+        self.clearInterfaceStats(aNetworks[index], callback);
+        return;
+      }
+
+      aResultCb(aError, aResult);
+    };
+
+    if (!aNetworks[index]) {
+      aResultCb(null, true);
+      return;
+    }
+    this.clearInterfaceStats(aNetworks[index], callback);
+  },
+
+  getCurrentStats: function getCurrentStats(aNetwork, aDate, aResultCb) {
+    if (DEBUG) {
+      debug("Get current stats for " + JSON.stringify(aNetwork) + " since " + aDate);
+    }
+
+    let network = [aNetwork.id, aNetwork.type];
+    if (aDate) {
+      this._getCurrentStatsFromDate(network, aDate, aResultCb);
+      return;
+    }
+
+    this._getCurrentStats(network, aResultCb);
+  },
+
+  _getCurrentStats: function _getCurrentStats(aNetwork, aResultCb) {
+    this.dbNewTxn(STATS_STORE_NAME, "readonly", function(txn, store) {
+      let request = null;
+      let upperFilter = [0, 1, "", aNetwork, Date.now()];
+      let range = IDBKeyRange.upperBound(upperFilter, false);
+      let result = { rxBytes:      0, txBytes:      0,
+                     rxTotalBytes: 0, txTotalBytes: 0 };
+
+      request = store.openCursor(range, "prev");
+
+      request.onsuccess = function onsuccess(event) {
+        let cursor = event.target.result;
+        if (cursor) {
+          result.rxBytes = result.rxTotalBytes = cursor.value.rxTotalBytes;
+          result.txBytes = result.txTotalBytes = cursor.value.txTotalBytes;
+        }
+
+        txn.result = result;
+      };
+    }.bind(this), aResultCb);
+  },
+
+  _getCurrentStatsFromDate: function _getCurrentStatsFromDate(aNetwork, aDate, aResultCb) {
+    aDate = new Date(aDate);
+    this.dbNewTxn(STATS_STORE_NAME, "readonly", function(txn, store) {
+      let request = null;
+      let start = this.normalizeDate(aDate);
+      let upperFilter = [0, 1, "", aNetwork, Date.now()];
+      let range = IDBKeyRange.upperBound(upperFilter, false);
+      let result = { rxBytes:      0, txBytes:      0,
+                     rxTotalBytes: 0, txTotalBytes: 0 };
+
+      request = store.openCursor(range, "prev");
+
+      request.onsuccess = function onsuccess(event) {
+        let cursor = event.target.result;
+        if (cursor) {
+          result.rxBytes = result.rxTotalBytes = cursor.value.rxTotalBytes;
+          result.txBytes = result.txTotalBytes = cursor.value.txTotalBytes;
+        }
+
+        let timestamp = cursor.value.timestamp;
+        let range = IDBKeyRange.lowerBound(lowerFilter, false);
+        request = store.openCursor(range);
+
+        request.onsuccess = function onsuccess(event) {
+          let cursor = event.target.result;
+          if (cursor) {
+            if (cursor.value.timestamp == timestamp) {
+              // There is one sample only.
+              result.rxBytes = cursor.value.rxBytes;
+              result.txBytes = cursor.value.txBytes;
+            } else {
+              result.rxBytes -= cursor.value.rxTotalBytes;
+              result.txBytes -= cursor.value.txTotalBytes;
+            }
+          }
+
+          txn.result = result;
+        };
+      };
+    }.bind(this), aResultCb);
+  },
+
+  find: function find(aResultCb, aAppId, aBrowsingTrafficOnly, aServiceType,
+                      aNetwork, aStart, aEnd, aAppManifestURL) {
+    let offset = (new Date()).getTimezoneOffset() * 60 * 1000;
+    let start = this.normalizeDate(aStart);
+    let end = this.normalizeDate(aEnd);
+
+    if (DEBUG) {
+      debug("Find samples for appId: " + aAppId +
+            " browsingTrafficOnly: " + aBrowsingTrafficOnly +
+            " serviceType: " + aServiceType +
+            " network: " + JSON.stringify(aNetwork) + " from " + start +
+            " until " + end);
+      debug("Start time: " + new Date(start));
+      debug("End time: " + new Date(end));
+    }
+
+    // Find samples of browsing traffic (isInBrowser = 1) first since they are
+    // needed no matter browsingTrafficOnly is true or false.
+    // We have to make two queries to database because we cannot filter correct
+    // records by a single query that sets ranges for two keys (isInBrowser and
+    // timestamp). We think it is because the keyPath contains an array
+    // (network) so such query does not work.
+    this.dbNewTxn(STATS_STORE_NAME, "readonly", function(aTxn, aStore) {
+      let network = [aNetwork.id, aNetwork.type];
+      let lowerFilter = [aAppId, 1, aServiceType, network, start];
+      let upperFilter = [aAppId, 1, aServiceType, network, end];
+      let range = IDBKeyRange.bound(lowerFilter, upperFilter, false, false);
+
+      let data = [];
+
+      if (!aTxn.result) {
+        aTxn.result = {};
+      }
+      aTxn.result.appManifestURL = aAppManifestURL;
+      aTxn.result.browsingTrafficOnly = aBrowsingTrafficOnly;
+      aTxn.result.serviceType = aServiceType;
+      aTxn.result.network = aNetwork;
+      aTxn.result.start = aStart;
+      aTxn.result.end = aEnd;
+
+      let request = aStore.openCursor(range).onsuccess = function(event) {
+        var cursor = event.target.result;
+        if (cursor){
+          // We use rxTotalBytes/txTotalBytes instead of rxBytes/txBytes for
+          // the first (oldest) sample. The rx/txTotalBytes fields record
+          // accumulative usage amount, which means even if old samples were
+          // expired and removed from the Database, we can still obtain the
+          // correct network usage.
+          if (data.length == 0) {
+            data.push({ rxBytes: cursor.value.rxTotalBytes,
+                        txBytes: cursor.value.txTotalBytes,
+                        date: new Date(cursor.value.timestamp + offset) });
+          } else {
+            data.push({ rxBytes: cursor.value.rxBytes,
+                        txBytes: cursor.value.txBytes,
+                        date: new Date(cursor.value.timestamp + offset) });
+          }
+          cursor.continue();
+          return;
+        }
+
+        if (aBrowsingTrafficOnly) {
+          this.fillResultSamples(start + offset, end + offset, data);
+          aTxn.result.data = data;
+          return;
+        }
+
+        // Find samples of app traffic (isInBrowser = 0) as well if
+        // browsingTrafficOnly is false.
+        lowerFilter = [aAppId, 0, aServiceType, network, start];
+        upperFilter = [aAppId, 0, aServiceType, network, end];
+        range = IDBKeyRange.bound(lowerFilter, upperFilter, false, false);
+        request = aStore.openCursor(range).onsuccess = function(event) {
+          cursor = event.target.result;
+          if (cursor) {
+            var date = new Date(cursor.value.timestamp + offset);
+            var foundData = data.find(function (element, index, array) {
+              if (element.date.getTime() !== date.getTime()) {
+                return false;
+              }
+              return element;
+            }, date);
+
+            if (foundData) {
+              foundData.rxBytes += cursor.value.rxBytes;
+              foundData.txBytes += cursor.value.txBytes;
+            } else {
+              // We use rxTotalBytes/txTotalBytes instead of rxBytes/txBytes
+              // for the first (oldest) sample. The rx/txTotalBytes fields
+              // record accumulative usage amount, which means even if old
+              // samples were expired and removed from the Database, we can
+              // still obtain the correct network usage.
+              if (data.length == 0) {
+                data.push({ rxBytes: cursor.value.rxTotalBytes,
+                            txBytes: cursor.value.txTotalBytes,
+                            date: new Date(cursor.value.timestamp + offset) });
+              } else {
+                data.push({ rxBytes: cursor.value.rxBytes,
+                            txBytes: cursor.value.txBytes,
+                            date: new Date(cursor.value.timestamp + offset) });
+              }
+            }
+            cursor.continue();
+            return;
+          }
+          this.fillResultSamples(start + offset, end + offset, data);
+          aTxn.result.data = data;
+        }.bind(this);  // openCursor(range).onsuccess() callback
+      }.bind(this);  // openCursor(range).onsuccess() callback
+    }.bind(this), aResultCb);
+  },
+
+  /*
+   * Fill data array (samples from database) with empty samples to match
+   * requested start / end dates.
+   */
+  fillResultSamples: function fillResultSamples(aStart, aEnd, aData) {
+    if (aData.length == 0) {
+      aData.push({ rxBytes: undefined,
+                  txBytes: undefined,
+                  date: new Date(aStart) });
+    }
+
+    while (aStart < aData[0].date.getTime()) {
+      aData.unshift({ rxBytes: undefined,
+                      txBytes: undefined,
+                      date: new Date(aData[0].date.getTime() - SAMPLE_RATE) });
+    }
+
+    while (aEnd > aData[aData.length - 1].date.getTime()) {
+      aData.push({ rxBytes: undefined,
+                   txBytes: undefined,
+                   date: new Date(aData[aData.length - 1].date.getTime() + SAMPLE_RATE) });
+    }
+  },
+
+  getAvailableNetworks: function getAvailableNetworks(aResultCb) {
+    this.dbNewTxn(STATS_STORE_NAME, "readonly", function(aTxn, aStore) {
+      if (!aTxn.result) {
+        aTxn.result = [];
+      }
+
+      let request = aStore.index("network").openKeyCursor(null, "nextunique");
+      request.onsuccess = function onsuccess(event) {
+        let cursor = event.target.result;
+        if (cursor) {
+          aTxn.result.push({ id: cursor.key[0],
+                             type: cursor.key[1] });
+          cursor.continue();
+          return;
+        }
+      };
+    }, aResultCb);
+  },
+
+  isNetworkAvailable: function isNetworkAvailable(aNetwork, aResultCb) {
+    this.dbNewTxn(STATS_STORE_NAME, "readonly", function(aTxn, aStore) {
+      if (!aTxn.result) {
+        aTxn.result = false;
+      }
+
+      let network = [aNetwork.id, aNetwork.type];
+      let request = aStore.index("network").openKeyCursor(IDBKeyRange.only(network));
+      request.onsuccess = function onsuccess(event) {
+        if (event.target.result) {
+          aTxn.result = true;
+        }
+      };
+    }, aResultCb);
+  },
+
+  getAvailableServiceTypes: function getAvailableServiceTypes(aResultCb) {
+    this.dbNewTxn(STATS_STORE_NAME, "readonly", function(aTxn, aStore) {
+      if (!aTxn.result) {
+        aTxn.result = [];
+      }
+
+      let request = aStore.index("serviceType").openKeyCursor(null, "nextunique");
+      request.onsuccess = function onsuccess(event) {
+        let cursor = event.target.result;
+        if (cursor && cursor.key != "") {
+          aTxn.result.push({ serviceType: cursor.key });
+          cursor.continue();
+          return;
+        }
+      };
+    }, aResultCb);
+  },
+
+  get sampleRate () {
+    return SAMPLE_RATE;
+  },
+
+  get maxStorageSamples () {
+    return VALUES_MAX_LENGTH;
+  },
+
+  logAllRecords: function logAllRecords(aResultCb) {
+    this.dbNewTxn(STATS_STORE_NAME, "readonly", function(aTxn, aStore) {
+      aStore.mozGetAll().onsuccess = function onsuccess(event) {
+        aTxn.result = event.target.result;
+      };
+    }, aResultCb);
+  },
+
+  alarmToRecord: function alarmToRecord(aAlarm) {
+    let record = { networkId: aAlarm.networkId,
+                   absoluteThreshold: aAlarm.absoluteThreshold,
+                   relativeThreshold: aAlarm.relativeThreshold,
+                   startTime: aAlarm.startTime,
+                   data: aAlarm.data,
+                   manifestURL: aAlarm.manifestURL,
+                   pageURL: aAlarm.pageURL };
+
+    if (aAlarm.id) {
+      record.id = aAlarm.id;
+    }
+
+    return record;
+  },
+
+  recordToAlarm: function recordToalarm(aRecord) {
+    let alarm = { networkId: aRecord.networkId,
+                  absoluteThreshold: aRecord.absoluteThreshold,
+                  relativeThreshold: aRecord.relativeThreshold,
+                  startTime: aRecord.startTime,
+                  data: aRecord.data,
+                  manifestURL: aRecord.manifestURL,
+                  pageURL: aRecord.pageURL };
+
+    if (aRecord.id) {
+      alarm.id = aRecord.id;
+    }
+
+    return alarm;
+  },
+
+  addAlarm: function addAlarm(aAlarm, aResultCb) {
+    this.dbNewTxn(ALARMS_STORE_NAME, "readwrite", function(txn, store) {
+      if (DEBUG) {
+        debug("Going to add " + JSON.stringify(aAlarm));
+      }
+
+      let record = this.alarmToRecord(aAlarm);
+      store.put(record).onsuccess = function setResult(aEvent) {
+        txn.result = aEvent.target.result;
+        if (DEBUG) {
+          debug("Request successful. New record ID: " + txn.result);
+        }
+      };
+    }.bind(this), aResultCb);
+  },
+
+  getFirstAlarm: function getFirstAlarm(aNetworkId, aResultCb) {
+    let self = this;
+
+    this.dbNewTxn(ALARMS_STORE_NAME, "readonly", function(txn, store) {
+      if (DEBUG) {
+        debug("Get first alarm for network " + aNetworkId);
+      }
+
+      let lowerFilter = [aNetworkId, 0];
+      let upperFilter = [aNetworkId, ""];
+      let range = IDBKeyRange.bound(lowerFilter, upperFilter);
+
+      store.index("alarm").openCursor(range).onsuccess = function onsuccess(event) {
+        let cursor = event.target.result;
+        txn.result = null;
+        if (cursor) {
+          txn.result = self.recordToAlarm(cursor.value);
+        }
+      };
+    }, aResultCb);
+  },
+
+  removeAlarm: function removeAlarm(aAlarmId, aManifestURL, aResultCb) {
+    this.dbNewTxn(ALARMS_STORE_NAME, "readwrite", function(txn, store) {
+      if (DEBUG) {
+        debug("Remove alarm " + aAlarmId);
+      }
+
+      store.get(aAlarmId).onsuccess = function onsuccess(event) {
+        let record = event.target.result;
+        txn.result = false;
+        if (!record || (aManifestURL && record.manifestURL != aManifestURL)) {
+          return;
+        }
+
+        store.delete(aAlarmId);
+        txn.result = true;
+      }
+    }, aResultCb);
+  },
+
+  removeAlarms: function removeAlarms(aManifestURL, aResultCb) {
+    this.dbNewTxn(ALARMS_STORE_NAME, "readwrite", function(txn, store) {
+      if (DEBUG) {
+        debug("Remove alarms of " + aManifestURL);
+      }
+
+      store.index("manifestURL").openCursor(aManifestURL)
+                                .onsuccess = function onsuccess(event) {
+        let cursor = event.target.result;
+        if (cursor) {
+          cursor.delete();
+          cursor.continue();
+        }
+      }
+    }, aResultCb);
+  },
+
+  updateAlarm: function updateAlarm(aAlarm, aResultCb) {
+    let self = this;
+    this.dbNewTxn(ALARMS_STORE_NAME, "readwrite", function(txn, store) {
+      if (DEBUG) {
+        debug("Update alarm " + aAlarm.id);
+      }
+
+      let record = self.alarmToRecord(aAlarm);
+      store.openCursor(record.id).onsuccess = function onsuccess(event) {
+        let cursor = event.target.result;
+        txn.result = false;
+        if (cursor) {
+          cursor.update(record);
+          txn.result = true;
+        }
+      }
+    }, aResultCb);
+  },
+
+  getAlarms: function getAlarms(aNetworkId, aManifestURL, aResultCb) {
+    let self = this;
+    this.dbNewTxn(ALARMS_STORE_NAME, "readonly", function(txn, store) {
+      if (DEBUG) {
+        debug("Get alarms for " + aManifestURL);
+      }
+
+      txn.result = [];
+      store.index("manifestURL").openCursor(aManifestURL)
+                                .onsuccess = function onsuccess(event) {
+        let cursor = event.target.result;
+        if (!cursor) {
+          return;
+        }
+
+        if (!aNetworkId || cursor.value.networkId == aNetworkId) {
+          txn.result.push(self.recordToAlarm(cursor.value));
+        }
+
+        cursor.continue();
+      }
+    }, aResultCb);
+  },
+
+  _resetAlarms: function _resetAlarms(aNetworkId, aResultCb) {
+    this.dbNewTxn(ALARMS_STORE_NAME, "readwrite", function(txn, store) {
+      if (DEBUG) {
+        debug("Reset alarms for network " + aNetworkId);
+      }
+
+      let lowerFilter = [aNetworkId, 0];
+      let upperFilter = [aNetworkId, ""];
+      let range = IDBKeyRange.bound(lowerFilter, upperFilter);
+
+      store.index("alarm").openCursor(range).onsuccess = function onsuccess(event) {
+        let cursor = event.target.result;
+        if (cursor) {
+          if (cursor.value.startTime) {
+            cursor.value.relativeThreshold = cursor.value.threshold;
+            cursor.update(cursor.value);
+          }
+          cursor.continue();
+          return;
+        }
+      };
+    }, aResultCb);
+  }
+};